U.S. patent number 7,316,766 [Application Number 11/138,403] was granted by the patent office on 2008-01-08 for electrochemical biosensor strip.
This patent grant is currently assigned to Taidoc Technology Corporation. Invention is credited to Chao-Wang Chen, Chun-Tung Chen, Tsai-Yun Lee, Chun-Hui Pi, Chia-Chi Wu, Shu-Mei Wu.
United States Patent |
7,316,766 |
Chen , et al. |
January 8, 2008 |
**Please see images for:
( Reexamination Certificate ) ** |
Electrochemical biosensor strip
Abstract
An electrochemical biosensor strip has a base, an electrode
system, an optional spacer and a cover. The electrode system is
laid on the base. The spacer is laid on the electrode system and
exposes a portion of the electrode system for electrical connection
with a meter and a different portion of the electrode system for
application of a test reagent. The cover is covered on the spacer
to form a cavity. Between the test reagent and the base, a
hydrophilic layer is laid between them for increasing the binding
effect of the test reagent on the base. The hydrophilic layer is
laid on the area excluding from the electrode system and laid on
the electrode system about 50% to 0% of the electrode system
corresponding to the test reagent. The hydrophilic layer will not
interfere with signal transmission of the electrode system so the
test is more accurate.
Inventors: |
Chen; Chun-Tung (Taipei,
TW), Lee; Tsai-Yun (Sindian, TW), Wu;
Shu-Mei (Taipei, TW), Wu; Chia-Chi (Kaohsiung,
TW), Pi; Chun-Hui (Yonghe, TW), Chen;
Chao-Wang (Taipei, TW) |
Assignee: |
Taidoc Technology Corporation
(Taipei, TW)
|
Family
ID: |
37462023 |
Appl.
No.: |
11/138,403 |
Filed: |
May 27, 2005 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20060266645 A1 |
Nov 30, 2006 |
|
Current U.S.
Class: |
204/403.02;
204/403.14 |
Current CPC
Class: |
G01N
27/3272 (20130101) |
Current International
Class: |
G01N
27/327 (20060101) |
Field of
Search: |
;205/777.5,778,792
;204/403.01-403.15 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
JPO English language translation of Shuzo et al. (JP 2004-004017
A). cited by examiner.
|
Primary Examiner: Noguerola; Alex
Claims
What is claimed is:
1. An electrochemical biosensor strip, comprising: a base; an
electrode system laid on the base and a portion of the electrode
system exposed for an electrical connection adapted to a meter and
a predetermined portion of the electrode system exposed for
applying a test reagent; a cover cooperating with the base to form
a cavity for drawing an analyte-containing fluid therein to react
with the test reagent; and a hydrophilic layer laid under the test
reagent and laid on an area of the base excluded from the electrode
system corresponding to the test reagent and also laid on the
electrode system about 50% to 0% of the electrode system
corresponding to the test reagent, wherein the hydrophilic layer
has a size corresponding to the test reagent.
2. The electrochemical biosensor strip as claimed in claim 1,
wherein the hydrophilic layer is water soluble cellulose,
surfactant, thickening agent, organic polar compound or a
combination thereof.
3. The electrochemical biosensor strip as claimed in claim 1,
wherein the hydrophilic layer is methylcellulose, carboxymethyl
cellulose, methylhydroxyethylcellulose,
methylhydroxypropylcellulose, hydroxyethylcellulose,
hydroxyethylcarboxymethylcellulose,
carboxymethylhydroxyethylcellulose or a combination thereof.
4. The electrochemical biosensor strip as claimed in claim 1,
wherein the electrode system comprises at least one working
electrode and the hydrophilic layer laid both on an area of the
base and the electrode system excluded from the working electrode
corresponding to the test reagent and also laid on the working
electrode about 50% to 0% of the working electrode corresponding to
the test reagent.
5. The electrochemical biosensor strip as claimed in claim 4,
wherein the hydrophilic layer laid on the working electrode is at
least one strip-like shape.
6. The electrochemical biosensor strip as claimed in claim 5,
wherein the hydrophilic layer laid on the working electrode is at
least one strip-like shape formed on a middle of the working
electrode.
7. The electrochemical biosensor strip as claimed in claim 4,
wherein the hydrophilic layer laid on the area excluded from the
working electrode is a plurality of strip-like shapes formed under
the test reagent.
8. The electrochemical biosensor strip as claimed in claim 1,
wherein the cover further comprises a concave unit formed
corresponding to the test reagent and outside of the test reagent
and the concave unit is semicircle-shape or semiellipse-shape.
9. The electrochemical biosensor strip as claimed in claim 1,
further comprising a spacer covered on the electrode system to
expose the portion of the electrode system for an electrical
connection adapted to a meter, having an opening formed in one side
of the spacer to expose the predetermined portion of the electrode
system for applying the test reagent.
10. The electrochemical biosensor strip as claimed in claim 9,
wherein the spacer further comprises an exhausting channel formed
extendedly from the opening and opened to another side of the
spacer.
11. The electrochemical biosensor strip as claimed in claim 9,
wherein the cover further has a hole corresponding to the test
reagent.
12. The electrochemical biosensor strip as claimed in claim 11,
wherein the cover further has a channel formed corresponding to the
opening of the spacer and communicating to the hole.
13. The electrochemical biosensor strip as claimed in claim 1,
further comprising a spacer covered on the electrode system to
expose the portion of the electrode system for an electrical
connection adapted to a meter, having an opening formed in one end
of the spacer to expose the predetermined portion of the electrode
system for applying the test reagent.
14. The electrochemical biosensor strip as claimed in claim 13,
wherein the spacer further has an exhausting channel communicated
with the opening to form a T-shape.
15. The electrochemical biosensor strip as claimed in claim 14,
further comprising an insulating substance laid on the electrode
system which has an opening formed corresponding to the opening of
the spacer.
16. The electrochemical biosensor strip as claimed in claim 1,
further comprising a rough unit formed on the base corresponding to
the test reagent and adjacent to the electrode system.
17. The electrochemical biosensor strip as claimed in claim 16,
wherein the rough unit is a plurality of lines.
18. The electrochemical biosensor strip as claimed in claim 1,
wherein the electrode system comprises at least three electrodes
and a short circuit is formed between two selected electrodes of
the at least three electrodes.
19. The electrochemical biosensor strip as claimed in claim 1,
wherein the electrode system comprises a silver layer laid on the
base and a carbon layer laid on the silver layer and the silver
layer has a X-shaped unit formed on the base and between the
electrodes and the carbon layer has an arrowhead shape unit formed
corresponding to the X-shaped unit.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to an electrochemical
biosensor strip. More particularly, the present invention relates
to an electrochemical biosensor strip that has a hydrophilic layer
laid under a test reagent and excluded from an electrode system
corresponding to the test reagent for increasing the test reagent
binding on a base and preventing the hydrophilic layer interfering
with signal transmission.
2. Description of the Related Art
Since the improvement of the science and technology, many tests can
be operated by users in house. In the market, many disposable
strips are used for measuring specific components in a biological
fluid and can be operated by users in house. Analytical biosensor
strips are useful in chemistry and medicine to determine the
presence and concentration of a biological analyte. Such strips are
needed, for example, to monitor glucose in diabetic patients and
lactate during critical care events. Biosensor strips are used in
the chemical industry, for example, to analyze complex mixtures.
They are also used in the food industry and in the biochemical
engineering industry. Biosensor strips are also useful in medical
research or in external testing. In external testing, they can
function in a non-invasive manner (i.e., where they come into
contact with blood withdrawn by a syringe or a pricking
device).
Conventional electrochemical biosensor strip has a base, an
electrode system, an insulating substrate, a test reagent and a
cover. The electrode system is laid on the base and comprises two
electrodes separated from each other. The insulating substrate is
laid down onto the electrode system and has a first opening and a
second opening. The first opening exposes portions of the electrode
system for electrical connection with a meter, which measures some
electrical property of a test sample after the test sample is mixed
with the test reagent of the strip. The second opening exposes a
different portion of the electrode system for application of the
test reagent to those exposed surfaces of electrode system. The
test reagent is a reagent that is specific for the test to be
performed by the strip. The test reagent may be applied to the
entire exposed surface area of the electrode system in the area
defined by the second opening. The cover is covered on the
electrode system and the test reagent for protecting the test
reagent.
However, since the base is prepared by polyethylene terephthalate
(PET) or polyvinyl chloride (PVC) which is hydrophobic, the test
reagent laid on the base is unstable. The strip is manufactured by
a sheet of the PET or PVC substance and the sheet is cut for
forming multiple strips after every needed substances are laid on
the sheet. When the cutting step is proceeding, the test reagent is
easy to shake off from the base. Besides, the electrode locates on
the base so as to protrude from the base such that a surface that
the test reagent layer laid on is not a flat plane. It will cause
the test reagent spread on the base unequally so as to interfere
with the detecting result.
SUMMARY OF THE INVENTION
One aspect of the present invention is to provide an
electrochemical biosensor strip which has a hydrophilic layer for
increasing a test reagent layer bond on a base strongly and which
dose not locate corresponding to an electrode system for avoiding
from interfering with signal transmission so as to increase test
accuracy.
Accordingly, the electrochemical biosensor strip of the present
invention comprises a base, an electrode system, a hydrophilic
layer, a test reagent and a cover. The electrode system is laid on
the base and a portion of the electrode system is utilized for
electrical connection with a mating meter, which measures some
electrical property of an analyte-containing fluid after an
analyte-containing fluid is mixed with the test reagent of the
strip. A predetermined portion of the electrode system is applied
for the test reagent to those exposed surfaces of electrode system.
The test reagent is a reagent that is specific for the test to be
performed by the strip. The test reagent may be applied to the
entire exposed surface area of the electrode system. The cover
locates on a top and mated with the base for providing a cavity so
as to draw the analyte-containing fluid into the electrochemical
biosensor strip by capillary phenomenon. Under the test reagent,
the hydrophilic layer is laid between the test reagent and the base
and laid on the base corresponding to the cavity and excluding from
the electrode system and laid on the electrode system about 50% to
0% of the electrode system corresponding to the test reagent. The
hydrophilic layer will let the test reagent bond strongly and
equally on the base and prevent from interfering with signal
transmission of the electrode system, and therefore, the test is
more accuracy.
Further scope of applicability of the present invention will become
apparent from the detailed description given hereinafter. However,
it should be understood that the detailed description and specific
examples, while indicating preferred embodiments of the invention,
are given by way of illustration only, since various changes and
modifications within the spirit and scope of the invention will
become apparent to those skilled in the art from this detailed
description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of an
electrochemical biosensor strip in accordance with the present
invention;
FIG. 2 is an exploded perspective view of the electrochemical
biosensor strip in FIG. 1;
FIG. 3A is a plan view of an area of a base corresponding to an
opening of a spacer of the electrochemical biosensor strip in FIG.
1 showing a distribution of an electrode system and a rough unit
corresponding to the opening of the spacer without laying a
hydrophilic layer and a test reagent;
FIG. 3B is a plan view of the area in FIG. 3A showing the
hydrophilic layer laid on the area without laying the test
reagent;
FIG. 4 is an exploded perspective view of a second embodiment of an
electrochemical biosensor strip in accordance with the present
invention;
FIG. 5 is a perspective view of a third embodiment of an
electrochemical biosensor strip in accordance with the present
invention; and
FIG. 6 is an exploded perspective view of the electrochemical
biosensor strip in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1 and 2, a first embodiment of an
electrochemical biosensor strip in accordance with the present
invention comprises a base (10), an electrode system (20), a spacer
(30), a hydrophilic layer (60), a test reagent (62) and a cover
(40).
The base (10) may be rectangular and preferably is an insulating
substance. The electrode system (20) is laid on the base (10) and
preferably comprises two layers that are a silver layer (22) and a
carbon layer (24). The silver layer (22) is laid on the base (10)
and the carbon layer (24) is laid on the silver layer (22). The
carbon layer (24) and the silver layer (22) respectively comprise
at least three electrodes that respectively have a first end and a
second end. In the drawings, the silver layer (22) has three
electrodes and the carbon layer (24) has four electrodes. There is
a short circuit formed between two electrodes of the carbon layer
(24) and the corresponding electrodes of the silver layer (22).
Other electrodes are separated so that the electrodes do not
interfere with the electrochemical events at the other electrode.
Preferably, one electrode of the electrodes that formed the short
circuit is a reference electrode. The short circuit is utilized to
switch on a mating meter. There is at least one working electrode
included in the electrode system (20).
The first ends of the electrodes are parallel and formed along a
long edge of the strip. The second ends of the electrodes are
defined corresponding to the test reagent (62). Preferably, the
silver layer (22) further has a forked shape unit (23) formed
between the electrodes. More preferably, the carbon layer (24)
further has an arrowhead shape unit (25) formed on the forked shape
unit (23) of the silver layer (22). When users are inserting wrong
direction of the strip, the users will see the forked shape unit
(23) for reminding the users that the direction is wrong. On the
contrary, the users will see the arrowhead shape unit (25) when the
inserting direction is correct.
The biosensor strip further has a rough unit (26) laid on the base
(10) and located corresponding to the test reagent (62).
Preferably, the rough unit (26) is a line or multiple lines and
more preferably laid on an outside of the second end of the
electrodes and adjacent to the electrodes. The rough unit (26) is
preferably prepared by electric conduction substance or
non-electric conduction substance. More preferably, the rough unit
(26) is prepared by carbon and separated from the electrode system
(20). For decreasing manufacturing cost, the rough unit (26) is
printed by carbon when the carbon layer (24) of the electrode
system (20) is printing. The rough unit (26) can increase the rough
of the base (10), and therefore, the test reagent (62) laid on the
base (10) will not easy to be shaking off when the strip is cut for
separating. In addition, the rough unit (26) is located on the
outside of the electrode system (20) so the rough unit (26) can
form a wall for protecting the test reagent (62) from falling.
The spacer (30) is laid on the electrode system (20) and comprises
an opening (32) and an exhausting channel (34). The electrodes will
be exposed when the spacer (30) is laid on the electrode system
(20) for electrical connection with a mating meter which measures
some electrical property of an analyte containing fluid after the
analyte-containing fluid is mixed with the test reagent (62) of the
strip. The opening (32) exposes a predetermined portion of the
electrode system (20) for application of the test reagent (62) to
the exposed surface of electrode system (20). The opening (32) is
preferably formed in a side of the spacer (30). The exhausting
channel (34) is communicates with the opening (32) for exiting air
and preferably the exhausting channel (34) formed extendedly from
the opening (32) and opened to another side. Therefore, the
exhausting channel (34) is used to increase the flow rate of an
analyte-containing fluid drawn in the opening (32) such that the
reaction is almost equal so as to increase the accuracy.
The hydrophilic layer (60) is laid on the base (10) corresponding
to the opening (32). Preferably, the hydrophilic layer (60) is laid
on an area of the base (10) corresponding to the opening (32) and
excluding from the electrode system (20) and laid on the electrode
system (20) about 50% to 0% of the electrode system (20)
corresponding to the opening (32). More preferably, the hydrophilic
layer (60) is laid on the area of the base (10) corresponding to
the opening (32) and excluding from the electrode system (20). On
another aspect, the hydrophilic layer (60) laid on the area of the
base (10) corresponding to the opening (32) and excluding from the
working electrode and laid on the working electrode about 50% to 0%
of the working electrode corresponding to the opening (32).
Preferably, the hydrophilic layer (60) is laid on the area of the
base (10) corresponding to the opening (32) and excluding from the
working electrode. Furthermore, the hydrophilic layer (60) is at
least one strip-like shape formed on the working electrode for
increasing the effect of the test reagent (62) spreading on the
working electrode and making the distribution of the test reagent
(62) lay on the hydrophilic layer (60) equally. The hydrophilic
layer (60) is a plurality of strip-like shape formed on the base
(10) corresponding to the opening (32) excluding from the working
electrode. The hydrophilic layer (60) preferably is composed of
hydrophilic substances, and more preferably, the hydrophilic layer
(60) is composed of soluble cellulose. The hydrophilic layer (60)
may be composed of methylcellulose (MC), carboxymethyl cellulose
(CMC), methylhydroxyethylcellulose (MHEC),
methylhydroxypropylcellulose (MHEC), methylhydroxypropylcellulose
(MHPC), hydroxyethylcellulose (HEC),
hydroxyethylcarboxymethylcellulose (HECMC),
carboxymethylhydroxyethylcellulose (CMHEC) or a combination
thereof. In addition, the hydrophilic layer (60) may be composed of
surfactant, strengthening of viscosity agent, organic polar
compound or a combination thereof. Preferably, the organic polar
compound has a boiling point at 200.degree. C. to 300.degree.
C.
With further reference to FIG. 3A, it is an enlarging figure
showing a portion of the base (10) corresponding to the opening
(32) of the spacer (30) which provides the distribution of the
electrode system (20) and the rough unit (26) on the base (10). It
is not covered with the hydrophilic layer (60). With further
reference to FIG. 3B, the hydrophilic layer (60) is covered on the
base (10) corresponding to the opening (32) of the spacer (30)
which is laid on the area excluding from the electrode system (20)
and laid on the electrode system (20) about 50% to 0% of the
electrode system (20) corresponding to the test reagent (62). The
hydrophilic layer (60) may be covered on the base (10) by printing,
evaporation or spotting etc.
The test reagent (62) is a reagent that is specific for the test to
be performed by the strip. The test reagent (62) may be applied to
the entire exposed surface area of the electrode system (20) in the
area defined by the opening (32). The cover (40) is covered on the
spacer (30) to protect the test reagent (62) and preferably
together with the opening (32) to form a cavity. When an
analyte-containing fluid, for example, a drop of blood, has been
drawn in the opening (32) of the strip, the analyte reacts with the
test reagent (62) and an output signal corresponding to a sensing
current is generated and is detected by a mating meter. Preferably,
the spacer (30) may be not needed and the cover (40) is cooperated
with the base (10) to form a cavity for drawing the
analyte-containing fluid by capillary phenomenon. The cover (40)
has a concave unit (46) that is formed corresponding to the opening
(32) of the spacer (30) to help the analyte-containing fluid drawn
into the opening (32) of the spacer (30) and increase variety
angles for drawing the fluid. Preferably, the concave unit (46) is
semicircle-shape or semi-ellipse-shape.
Since the base (10) is manufactured by hydrophobic substances, the
test reagent (62) is not easy to bind on the base (10) strongly.
The electrochemical biosensor strip in accordance with the present
invention provides a hydrophilic layer (60) laid on the base before
the test reagent (62) laid on the base (10). The hydrophilic layer
(60) will let the base (10) favorite for binding the test reagent
(62) so as to increase the effect of the test regent (62) spreading
on the base (10) and make the test reagent (62) distribute equally.
Besides, if the hydrophilic layer (60) is laid on the electrode
system (20) not equally (20), the signal transmission of the
electrode system (20) will decay and let the distribution of the
test reagent (62) not equally. Since the hydrophilic layer (60)
will interfere with signal transmission, the hydrophilic layer (60)
must exclude from the electrode system (20). Therefore, the
hydrophilic layer (60) laid on the area exception from the
electrode system (20) corresponding to the test reagent (62) and
laid on the electrode system (20) about 50% to 0% of the electrode
system (20) corresponding to the test reagent (62).
With reference to FIG. 4, a second embodiment of the
electrochemical biosensor strip in accordance with the present
invention comprises a base (10), an electrode system (20), a spacer
(30), a hydrophilic layer (60), a test reagent (62) and a cover
(40), which structure is almost the same with the first embodiment
of the electrochemical biosensor strip except that the cover (40)
further has a hole (42) and a channel (44) and the spacer (30) does
not has the exhausting channel. The hole (42) is formed
corresponding to the opening (32) of the spacer (30). Preferably,
the channel (44) opens to the opening (32) and communicates with
the hole (42). The channel (44) and the hole (42) are both used to
increase the flow rate of an analyte-containing fluid drawn into
the opening (32).
With reference to FIGS. 5 and 6, a third embodiment of the
electrochemical biosensor strip in accordance with the present
invention comprises a base (10a), an electrode system (20a), an
insulating substance (50), a spacer (30a), a hydrophilic layer
(60a), a test reagent (62a) and a cover (40a). The base (10a) may
be rectangular and preferably is an insulating substance. The
electrode system (20a) is laid on the base (10a) and preferably
comprises two layers that are a silver layer and a carbon layer.
The carbon layer and the silver layer respectively comprise at
least three electrodes that respectively have a first end and a
second end. The first ends of the electrodes are parallel and
formed along a long edge of the strip. The second ends of the
electrodes are defined corresponding to the test reagent (62a) and
preferably are parallel with a short edge of the strip. The spacer
(30a) is laid on the electrode system (20a). The electrodes will be
exposed as the spacer (30a) is laid on the electrode system (20a)
for electrical connection with a mating meter which measures some
electrical property of an analyte-containing fluid after the
analyte-containing fluid is mixed with the test reagent (62a) of
the strip. Preferably, a rough unit (26a) formed on the base (10a)
and more preferably the rough unit (26a) is formed on one end of
the base (10a). In the drawing, the rough unit (26a) is parallel
with one end of the electrode and near an outside of the base (10a)
corresponding to the test reagent (62a). Preferably, the rough unit
(26a) is formed adjacent to the electrode and more preferably is
formed outside and parallel with the second ends of the
electrodes.
The spacer (30a) comprises an opening (32a) formed in an end of the
spacer (30a) and an exhausting channel (34a) defined communicating
with the opening (32a). The opening (32a) exposes a predetermined
portion of the electrode system (20a) for application of the test
reagent (62a) to the exposed surface of electrode system (20a).
Preferably, the opening (32a) and the exhausting channel (34a) is
formed a T shape. The opening (32a) is used for introducing a
sample into the strip. The insulating substance (50) is laid on the
base (10a) and has an opening (52) formed corresponding to the
opening (32a) of the spacer (30a). The test reagent (62a) is laid
corresponding to the opening (52) of the insulating substance (50)
and the opening (32a) of the spacer (30a). The electrode system
(20a) has three electrodes and there is a short circuit between two
electrodes of the three electrodes.
The hydrophilic layer (60a) is laid on the base (10a) corresponding
to the opening (32a). Preferably, the hydrophilic layer (60a) is
laid on an area of the base (10a) corresponding to the opening
(32a) and excluding from the electrode system (20a) and laid on the
electrode system (20a) about 50% to 0% of the electrode system
(20a) corresponding to the opening (32a). More preferably, the
hydrophilic layer (60a) is laid on the area of the base (32a)
corresponding to the opening (32a) excluding from the electrode
system (20a). On another aspect, the hydrophilic layer (60a) is
laid on the area corresponding to the opening (32a) excluding from
the working electrode and laid on the working electrode about 50%
to 0% of the working electrode corresponding to the opening (32a).
Preferably, the hydrophilic layer (60a) is laid on the area of the
base (10a) corresponding to the opening (32a) and excluding from
the working electrode.
The cover (40a) has a concave unit (46a) formed therein and
corresponding to the opening (32a). The concave unit (46a) can
increase receiving angles for drawing the analyte-containing fluid
into the opening (32a) such that the analyte-containing fluid can
be drawn into the opening (32a) more rapidly.
In accordance with the present invention, the electrochemical
biosensor strip has a hydrophilic layer laid between the base and
the test reagent so as to increase the binding effect and the
stability of the test reagent on the base. In addition, since the
hydrophilic layer laid on the electrode system will interfere with
the signal transmission and let the signal decay so as to decrease
the signal transmission and to decrease test accuracy. Further, if
the hydrophilic layer is laid on the electrode system not equally,
the test reagent will not uniformly spread on the electrode system.
Therefore, the hydrophilic layer is laid on the area of the base
corresponding to the test reagent excluding from the electrode
system and laid on the electrode system about 50% to 0% of the
electrode system corresponding to the test reagent. On the
electrode system, a few part of the hydrophilic layer laid on the
electrode system will let the test reagent spread out equally on
the electrode system. It will also avoid the hydrophilic layer from
interfering with the signal transmission.
For example, if the hydrophilic layer is laid on the working
electrode completely, the signal will decay so as to decrease test
accuracy. In general, the working electrode is laid about 30% of
area that the base corresponding to the opening of the spacer and
therefore, if the hydrophilic layer is laid on the base exception
of the working electrode, the hydrophilic layer is laid about 70%
of the area that the base corresponding to the opening of the
spacer. That time, the signal produced by the reaction of the test
reagent and the analyte-containing fluid will not be interfered
because of the hydrophilic layer is not laid on the electrode
system. If the hydrophilic layer is covered on the electrode system
about 10% of the electrode system corresponding to the opening of
the spacer, the hydrophilic layer is laid on the base about 73% of
the area that the base corresponding to the opening of the spacer.
It will not only increase the effect of the test reagent spreading
on the electrode system but also decrease the noise signal to 90%
so as to increase the intensity of the signal.
Furthermore, when the intensity of the signal is increasing, the
amount of the test reagent, such as the amount of the enzyme, will
decrease to achieve the same detecting efficiency so as to decrease
manufacturing cost. Besides, the electrochemical biosensor strip is
manufactured small nowadays so the area of the test reagent is
small for decreasing needed amount of the analyte-containing fluid
such that the signal is in relation to small. Because of the
electrochemical biosensor strip of the present invention can
approve to decrease noise and increase the intensity of the signal
so as to increase test accuracy.
On the other hand, since the electrode system is laid on the base,
the surface of the base for laying the test reagent is not a plane
and showing concave areas that are the areas excluding from the
electrode system. When the test reagent is directly laid on the
base in this situation, it is difficult for the test reagent to
spread on the base equally. The electrochemical biosensor strip of
the present invention provides the hydrophilic layer laid on the
base before the test reagent laid on the base so the hydrophilic
layer may be full with the concave areas of the base corresponding
to the test reagent and let the area of the base corresponding to
the test reagent form a plane benefit for the test reagent
spreading on the base equally. Therefore, the test reagent will
bind on the base more stable so as to decrease the difference
between each electrochemical biosensor strip and promote
manufacturing quality.
Other embodiments of the invention will appear to those skilled in
the art from consideration of the specification and practice of the
invention disclosed herein. It is intended that the specification
and examples to be considered as exemplary only, with a true scope
and spirit of the invention being indicated by the following
claims.
* * * * *